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Follow-up patches will add support for fentry/fexit programs as well. > > While at it, mark bpf_tracing_func_proto() as static to make it obvious that > it's only used from within the kernel/trace/bpf_trace.c. > > Cc: Peter Zijlstra > Signed-off-by: Andrii Nakryiko > --- > include/linux/bpf.h | 3 --- > include/uapi/linux/bpf.h | 16 ++++++++++++++++ > kernel/trace/bpf_trace.c | 35 +++++++++++++++++++++++++++++++++- > tools/include/uapi/linux/bpf.h | 16 ++++++++++++++++ > 4 files changed, 66 insertions(+), 4 deletions(-) > > diff --git a/include/linux/bpf.h b/include/linux/bpf.h > index 74b35faf0b73..94ebedc1e13a 100644 > --- a/include/linux/bpf.h > +++ b/include/linux/bpf.h > @@ -2110,9 +2110,6 @@ extern const struct bpf_func_proto bpf_btf_find_by_name_kind_proto; > extern const struct bpf_func_proto bpf_sk_setsockopt_proto; > extern const struct bpf_func_proto bpf_sk_getsockopt_proto; > > -const struct bpf_func_proto *bpf_tracing_func_proto( > - enum bpf_func_id func_id, const struct bpf_prog *prog); > - > const struct bpf_func_proto *tracing_prog_func_proto( > enum bpf_func_id func_id, const struct bpf_prog *prog); > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index bc1fd54a8f58..96afeced3467 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -4856,6 +4856,21 @@ union bpf_attr { > * Get address of the traced function (for tracing and kprobe programs). > * Return > * Address of the traced function. > + * > + * u64 bpf_get_user_ctx(void *ctx) > + * Description > + * Get user_ctx value provided (optionally) during the program > + * attachment. It might be different for each individual > + * attachment, even if BPF program itself is the same. > + * Expects BPF program context *ctx* as a first argument. > + * > + * Supported for the following program types: > + * - kprobe/uprobe; > + * - tracepoint; > + * - perf_event. I think it is possible in the future we may need to support more program types with user_ctx, not just u64 but more than 64bit value. Should we may make this helper extensible like long bpf_get_user_ctx(void *ctx, void *user_ctx, u32 user_ctx_len) The return value will 0 to be good and a negative indicating an error. What do you think? > + * Return > + * Value specified by user at BPF link creation/attachment time > + * or 0, if it was not specified. > */ > #define __BPF_FUNC_MAPPER(FN) \ > FN(unspec), \ > @@ -5032,6 +5047,7 @@ union bpf_attr { > FN(timer_start), \ > FN(timer_cancel), \ > FN(get_func_ip), \ > + FN(get_user_ctx), \ > /* */ > > /* integer value in 'imm' field of BPF_CALL instruction selects which helper > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c > index c9cf6a0d0fb3..b14978b3f6fb 100644 > --- a/kernel/trace/bpf_trace.c > +++ b/kernel/trace/bpf_trace.c > @@ -975,7 +975,34 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { > .arg1_type = ARG_PTR_TO_CTX, > }; > > -const struct bpf_func_proto * > +BPF_CALL_1(bpf_get_user_ctx_trace, void *, ctx) > +{ > + struct bpf_trace_run_ctx *run_ctx; > + > + run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); > + return run_ctx->user_ctx; > +} > + > +static const struct bpf_func_proto bpf_get_user_ctx_proto_trace = { > + .func = bpf_get_user_ctx_trace, > + .gpl_only = false, > + .ret_type = RET_INTEGER, > + .arg1_type = ARG_PTR_TO_CTX, > +}; > + [...]